Protractor

Protractor is © 2003, myJanee.com and is used here by permission.

Technically, you won't need the bottom half of the protractor but that part may still be useful when you are looking at the lower zone of a sample. You can see if a lower extender stroke goes straight down or if it bends toward the left or the right. That is useful information.

Besides, Janee's version is much prettier protractor than others I was able to find. Let's hope it works for us.